Bowthruster woes

[ChrisPy]

So my Vetus bowthruster stopped working.

 

I have had trouble with the mickey mouse connectors for the control wires, which didn't help. Connecting the control panel directly to the thruster (bypassing 15metres of control cable) proved that the connectors were unreliable. The push together plastic male/female connectors will be replaced with chocblocks at either end.

 

But still the motor wouldn't start reliably.

 

I took it off and bench checked it.

With direct cables it turned both ways.

With jumpers on the control circuit it worked intermittently one way and not the other way.

Took it to the local auto electrical specialists who do motor rewinds, etc.

3 days later - "we need a new solenoid pack before we can test the motor".

Checked with Vetus agent - 275squid plus VAT.

Suspected that a standard contactor switch would do the job.

I know nothing about contactors, but I searched the web and found Albright who have one in their catalogue for about 80squid that seemed to meet the duty specification.

Albright contactors are used in electric vehicles, so an auto electrician should be aware of them and recognise one when he saw it.

Back to the electricians - removed the unit from their care, and discovered the Vetus part number and the Albright part number are actually the same.

Went on Albright's website - full instructions for dismantling the contactor, and a parts diagram.

Took it apart, found a burnt contact, ordered from Albight for 6squid, received, fitted, OK.

 

So with only a smattering of knowledge and an hour on the internet I solved a problem that the specialist couldn't be bothered with.

 

The moral is - Do It Yourself. ...... and don't rely on the marine agency for spares or service because most items are bog standard components.

 

The quandary is - why should the contacts burn out? The location of the thruster is deep within the cabin and is not conducive to corrosion. The thruster has rarely been used - maybe the lack of use caused the contacts to stick although I am not aware of the thruster ever 'running on' when the press button was released.

Edited April 25, 2009 by ChrisPy

[Gibbo]

The quandary is - why should the contacts burn out? The location of the thruster is deep within the cabin and is not conducive to corrosion. The thruster has rarely been used - maybe the lack of use caused the contacts to stick although I am not aware of the thruster ever 'running on' when the press button was released.

 

The contactor has almost certainly had a tiny bit of dirt on the contact. This increases the resistance very slighly, it then gets hot when running and carbons up. Once it's started it continually gets worse with no possibility of ever getting better. You were just unlucky. Albright relays are the DBs.

 

Gibbo

[ChrisPy]

The contactor has almost certainly had a tiny bit of dirt on the contact. This increases the resistance very slighly, it then gets hot when running and carbons up. Once it's started it continually gets worse with no possibility of ever getting better. You were just unlucky. Albright relays are the DBs.

 

Gibbo

And being a sealed unit (it has 4 blanking plates closing the apertures near the contacts) there seems no reason why there was any dirt ingress.

The fixed contact was also slightly burnt, so I filed it down smooth (like a pad of soft solder metal on the copper busbar). I hope this will be OK.

 

What p*sses me off is that so many so-called tradesmen and specialists just follow the new religion of "if it's broke, buy a new unit". FFS I bought a washing machine from Argos for half the price Vetus quoted just for a contactor!

[tomsk]

Your first mistake was specing a BT lol, a stout pole would have been maintenance free!

[Timleech]

Might the dodgy control connections have contributed to the arcing?

 

Tim

[Gibbo]

And being a sealed unit (it has 4 blanking plates closing the apertures near the contacts) there seems no reason why there was any dirt ingress.

The fixed contact was also slightly burnt, so I filed it down smooth (like a pad of soft solder metal on the copper busbar). I hope this will be OK.

 

What p*sses me off is that so many so-called tradesmen and specialists just follow the new religion of "if it's broke, buy a new unit". FFS I bought a washing machine from Argos for half the price Vetus quoted just for a contactor!

 

The blanking plates will stop big bits but they won't stup dust getting in.

 

Filing might not work. The contacts are coated with a special alloy to resist oxidisation. Well they were. They're not now you've filed it off Gentle polishing works better.

 

Gibbo

[ChrisPy]

The blanking plates will stop big bits but they won't stup dust getting in.

 

Filing might not work. The contacts are coated with a special alloy to resist oxidisation. Well they were. They're not now you've filed it off Gentle polishing works better.

 

Gibbo

From Albright website: They have double breaking main contacts with silver alloy contact tips, which are weld resistant, hard wearing and have excellent conductivity.

 

OK so I'll invest in a new top body for the contactor as well (the fixed contact strip is included in the top body part).

Fix it next time I'm home.

 

Driving the boat backwards into the marina berth and doing a 90degree turn (like on the car driving test) into the parking space without a thruster is challenging. And Tomsk : no, a pole wouldn't help. All bows, prows and shiny chrome davits and pulpits, nothing to pole off

Edited April 25, 2009 by ChrisPy

[blackrose]

Your first mistake was specing a BT lol, a stout pole would have been maintenance free!

 

But I doubt the person on the bow pushing the pole would be maintenance free!

Edited April 27, 2009 by blackrose

[markmiller]

Is this black thing the contact ?

Thruster wasnt working so took it to be seviced....had corroded in places.

Refitted it and still didnt work .

Cleaned and checked all connections...checked battery all good. Did work once for a brief push then stopped. FEW days later both sides worked but now stopped again !

Took it apart for the 100 th time....checked all brushes and cables....still not working.When i push the control panel i get a buzz and a click from the thruste but now action .....any clues to what i can do next anyone ?

Oh and checked the propeler through inspection hatch....something i wouldnt do again in a hurry....got nipped by a crayfish. ANY HELP much appreciated

Thanks

Mark

Edited June 1, 2017 by markmiller

[blackrose]

On 2017-6-1 at 14:36, markmiller said:

Took it apart for the 100 th time....checked all brushes and cables....still not working.When i push the control panel i get a buzz and a click from the thruste but now action .....any clues to what i can do next anyone ?

What voltage are you getting from your BT batteries (at rest with no charge or discharge). You need to be seeing between about 12.2v - 13.6v. If they're below 12v they're not charged adequately. These are very general voltages so someone with more electrical knowledge may wish to correct me. 

Where are the BT batteries located? They should be close to the motor. Are they wet-lead/acid and if so have you checked the water levels recently? 

What sort of length and cross-section are the cables from the batteries to the motor. Mine are are 70mm2 and less than a metre long.

Edited June 4, 2017 by blackrose

[Murflynn]

Mike is correct.

In my case I found the contactor couldn't hold the contact because the volts under load were inadequate.  The contacts 'chattered' and burnt the mating surfaces so there was then no ability to conduct the big (400A) current required.

the volts were inadequate because I didn't have a dedicated battery adjacent to the thruster.

new Allbright contacts, additional battery, never looked back. 

 

[WotEver]

2 hours ago, blackrose said:

What voltage are you getting from your BT batteries (at rest with no charge or discharge).

And what voltage are you seeing across the BT batteries when the button is pressed? (obviously this will require two of you) 

[markmiller]

On 25/04/2009 at 10:27, Gibbo said:

 

The contactor has almost certainly had a tiny bit of dirt on the contact. This increases the resistance very slighly, it then gets hot when running and carbons up. Once it's started it continually gets worse with no possibility of ever getting better. You were just unlucky. Albright relays are the DBs.

 

Gibbo

Hi dont suppose you know the part number ?think i have the same problem !

[WotEver]

1 hour ago, markmiller said:

Hi dont suppose you know the part number ?think i have the same problem !

Gibbo’s no longer a participant on this forum - that’s a 9 1/2 year old post you’re quoting. 

 

I’m sure Albright would be happy to point you in the right direction if you contact them: http://www.albrightinternational.com/

Edited November 4, 2018 by WotEver

[markmiller]

Thank you

[nb Innisfree]

Oh Gibbo, wherefore art thou Gibbo!

[WotEver]

58 minutes ago, nb Innisfree said:

Oh Gibbo, wherefore art thou Gibbo!

Happily selling his stuff to the military...

 

[rusty69]

Cos thats his name (well kind of) 

Edited November 5, 2018 by rusty69